Traditional grammar checkers check a document against a set grammar reference, identify violations of that reference, and offer the user a grammar correction indicated for that particular error by the reference. While such grammar checkers perform a valuable function, there is a limit to what they can accomplish. Even though a large library of grammar rules may be stored, natural human languages tend to be filled with matters of context, nuance, and ambiguity, that resist rigid application of rote rules. Grammar checkers also may be encoded with certain choices of rules in accordance with one or another particular set of prescriptive guidelines, but which are out of step with a properly descriptive grammar that genuinely reflects actual language usage by its native speakers, or at least by a large segment thereof. Such prescriptive guidelines may also enshrine grammatical rules that are ultimately arbitrarily based on one or another grammatical school of thought, but which run counter to actual usage in traditional, mainstream, widely esteemed exemplars of the language. Prescriptive, arbitrary, or rigidly uniform grammar rules are also unlikely to accurately reflect shifts in usage appropriate to different styles of writing, different target audiences, and different registers of language. The same subtleties in grammar and usage that are prohibitively difficult for a traditional grammar checker to distinguish are also unlikely to be easily accessed in a reference work, particularly for non-native speakers of the language in question, for whom there is no easy substitute for long-term experience with native usage in context.
The discussion above is merely provided for general background information and is not intended to be used as an aid in determining the scope of the claimed subject matter.